Ice-Making Machine

ABSTRACT

An ice maker comprises a frame ( 15 ), a tray ( 1 ) which is pivotable in the frame ( 15 ) about an axis and which has a plurality of compartments ( 4 ) arranged in a number of rows and separated from one another by partition walls ( 3 ), and a motor ( 22 ) for driving a pivot movement of the tray ( 1 ) about the axis, the motor being coupled to the tray ( 1 ) by way of an eccentric mechanism ( 25, 26, 28 ).

The present invention relates to an automatic ice maker with a frame, a tray which is pivotable in the frame about an axis and which has a plurality of compartments arranged in a number of rows and separated from one another by partition walls, and a motor for driving a pivot movement of the tray about the axis between an upright setting of the tray in which water in the compartments can freeze and an emptying setting in which the openings of the compartments face downwardly and the finished pieces of ice can drop out of the compartments.

An ice maker of this kind is known from, for example, U.S. Pat. No. 6,571,567 B2.

In the case of this conventional ice maker a motor subassembly is coupled directly to the pivot axis of the tray. The freedom of movement of the tray is not sufficient for a 360° rotation about the pivot axis. In operation it therefore has to be pivoted back and forth between the upright setting and the emptying setting. This requires a directionally controllable motor and a control circuit for the motor, which is capable of establishing at all times the correct rotational direction of the motor on the basis of a current setting of the tray and an operational phase of the ice-making in which the ice maker is instantaneously disposed.

The object of the invention is to indicate an ice maker which is capable of correctly driving the pivot movement of the ice-maker tray at any time without requiring a decision about the rotational direction of a motor driving the pivot movement.

The object is fulfilled in that in the case of an ice maker of the above-indicated kind the tray is coupled to the motor by way of an eccentric mechanism. The eccentric element of such a mechanism executes a circulatory motion about a fulcrum which, seen transversely to the axis of rotation, has a reciprocating oscillatory component. This component is usable in order to drive, in each period, a complete pivot oscillation of the tray without a change in direction of the drive motor being required for that purpose.

The eccentric mechanism preferably comprises a linearly displaceable oscillatory body carrying a rack which meshes with a gearwheel connected with the tray. Any desired pivot stroke of the tray can be easily constructed with such an arrangement.

An eccentric element is preferably in engagement with a rail which extends at the oscillatory body transversely to the direction of movement thereof in order to convert the circulatory motion of the eccentric element into a reciprocating motion of the oscillatory body.

According to a simple embodiment the rail is a slot and the eccentric element a pin engaging in the slot.

The tray is pivotable between an upright setting, in which water in the compartments of the tray can freeze, and an emptying setting, in which the openings of the compartments face downwardly, preferably also between these settings, and a tilted setting in which the compartments communicate via the upper edges of the partition walls. At least one of these three settings, preferably even two of them, respectively corresponds or correspond with a point of reversal of the movement of the oscillatory body. In the vicinity of the point of reversal the oscillatory body moves, even in the case of a rotational speed of the eccentric element assumed to be constant, in each instance particularly slowly, i.e. the dependence of the setting of the oscillatory body on the phase of the eccentric is small, so that the respective setting can be exactly set even when the eccentric phase is not precisely detected or the drive is subject to inaccuracies.

It can therefore suffice to control, with the help of a sensor arranged at the tray for detection of the setting thereof, only the exact running into that one of the three above-mentioned settings which does not correspond with a point of reversal. However, with the help of the sensor also the respective settings corresponding with the points of reversal can be precisely set in particularly simple manner. Whilst, when with such a sensor a stop setting between the points of reversal is detected and the motor is halted the tray always still continues to pivot a small amount until the motor comes to rest, such a further rotation at the points of reversal does not have any effect on the setting of the tray.

In order to facilitate removal of the finished pieces of ice from the mould the compartments preferably have the form of a segment of a body rotation. A piece of ice can be removed from these compartments in particularly simple manner in that it slides in circumferential direction of the body of rotation without, as in the case of a conventional block-shaped piece of ice of the type under consideration from, for example, U.S. Pat. No. 6,571,567 B2, forming, during removal from the mould, between the base of the compartment and the ice body a cavity which obstructs removal from the mould as long as there is no equalisation of an underpressure prevailing in the cavity.

The compartments of the ice-maker tray are preferably arranged in at least one row and a wall extending above the upper edge of partition walls separating the rows from one another is provided at a longitudinal side of each row of compartments and at least a part of the transverse sides thereof. This construction of the ice-maker tray allows this to be brought into an inclined state in which water filled into the compartments floods over the partition walls in a region adjoining the protruding wall so that exactly the same water state can be achieved in all compartments. If such a tray is, for freezing, pivoted into an upright state in which the partition walls extend substantially horizontally and are no longer flooded over, pieces of ice cleanly separated from one another and with exactly the same size can be produced.

An electric heating device can be provided at the ice-maker tray in order to accelerate and facilitate mould removal of finished pieces of ice through thawing at the surface.

In order to achieve an intensive heat exchange with the environment the tray can be provided with protruding heat exchange exchange ribs. These ribs can at the same time serve for mounting a rod-shaped heating device inserted therebetween.

Further features and advantages of the invention are evident from the following description of examples of embodiment with reference to the accompanying figures, in which:

FIG. 1 shows an exploded illustration of an automatic ice maker according to a preferred embodiment of the invention;

FIG. 2 shows a perspective view of the ice maker of FIG. 1 in assembled state with ice-maker tray in tilted setting;

FIG. 3 shows a front view of the ice maker of FIG. 1 or 2 in the direction of the pivot axis;

FIG. 4 shows the view of FIG. 3 with partly cut-away sensor housing;

FIG. 5 shows a view, which is analogous to FIG. 2, with ice-maker tray in upright setting;

FIG. 6 shows a view, which is analogous to FIG. 4, with the ice-maker tray in upright setting;

FIG. 7 shows a perspective view analogous to FIGS. 2 and 5 with the ice-maker tray in emptying setting;

FIG. 8 shows a view analogous to FIG. 4 or 6;

FIG. 9 shows a perspective exploded view from below of the ice-maker tray;

FIG. 10 shows a schematic front view of a second embodiment of the ice maker; and

FIG. 11 shows a schematic front view of a third embodiment of the ice maker.

FIG. 1 shows an automatic ice cube maker according to the present invention in an exploded perspective view. It comprises a tray 1 in the form of a channel with a semi-cylindrical base, which is closed at its ends by respective transverse walls 2 and is divided by partition walls 3, which are arranged at uniform spacings, into a plurality of identically shaped compartments 4, here seven units, with a semi-cylindrical base. Whereas the partition walls 3 at the longitudinal wall 5 remote from the viewer adjoin flushly, the longitudinal wall 6 facing the viewer is prolonged above the upper edges of the partition walls 3. Whilst the partition walls 3 are exactly semicircular, the transverse walls 2 each have a sector 7, which goes out above the semicircular shape, in correspondence with the protrusion of the front longitudinal wall 6.

The tray 1 is shown in a tilted setting in which the upper edges of the segments 7 extend substantially horizontally, whilst those of the partition walls 3 are inclined towards the longitudinal wall 6.

The tray 1 can be a plastics material moulded part, but preferably, due to the good capability of thermal conductance, it is constructed as a cast part of aluminium.

A hollow cylinder 11 is mounted at one of the transverse walls 2 of the tray 1; it serves for protected accommodation of a coiled power supply cable 12 serving for supply of current to a heating device 13, which is not visible in the figure, accommodated at the underside of the tray 1 (see FIG. 9). The tray 1 lies completely within a notional prolongation of the circumferential surface of the hollow cylinder 11, which at the same time represents the smallest possible cylinder into which the tray fits. An axial spigot 14, which protrudes from the transverse wall 2 facing the viewer, extends on the longitudinal centre axis of the hollow cylinder 11.

A frame moulded from plastics material is denoted by 15. It has an upwardly and downwardly open cavity 16 which is provided for mounting of the tray 1 therein. Bearing bushes 19, 20 for the pivotable mounting of the tray 1 are formed at the end walls 17, 18 of the cavity 16. A longitudinal wall of the cavity 16 is formed by a box 21, which is provided for reception of a drive motor 22 as well as various electronic components for control of operation of the ice maker. Mounted on the shaft of the drive motor 22 is a pinion 23 which can be seen better in each of FIGS. 3, 4, 6 and 8 than in FIG. 2. When the ice maker is in fully mounted state the pinion 23 finds space in a cavity 24 of the end wall 17. It forms there, together with a gearwheel 25, a speed step-down transmission.

The gearwheel 25 carries a pin 26 which protrudes in axial direction and which is provided for engaging in a vertical slot 27 of an oscillatory body 28. The oscillatory body 28 is guided to be horizontally displaceable with the help of pins 29 which protrude from the end wall 17 into the cavity 24 and which engage in a horizontal slot 30 of the oscillatory body. A toothing 31 formed at a lower edge of the oscillatory body 28 meshes with a gearwheel 32, which is provided for the purpose of being plugged onto the axial spigot 14 of the tray 1 to be secure against rotation relative thereto.

A cover plate 33 screw-connected to the open side of the end wall 17 closes the cavity 24. A fastening flange 34 with straps 35 protruding laterally beyond the end wall 17 serves for mounting the ice maker in a refrigerating appliance. A base plate 36 closes the box 21 at the bottom.

FIG. 2 shows, as seen from the side of the end wall 18 and the box 21, the ice maker with the tray 1 in tilted setting in perspective view. The upper edges of the sectors 7 at the transverse walls 2 of the tray 1 extend horizontally.

FIG. 3 shows a front view of the ice maker from the side of the end wall 17, wherein cover plate 33 and fastening flange 34 have been omitted in order to give free view into the cavity 24 of the end wall 17. The configuration shown here is that in which the ice maker is mounted together. Various markings indicate a correct positioning of individual parts relative to one another. A first pair of markings 37, 38 is disposed at the end wall 17 itself and at the gearwheel 25 carrying the pin 26. When these markings 37, 38 are, as shown in the figure, aligned exactly with one another the pin 26 is disposed in a 3 o'clock setting, i.e. on the point, which lies furthest to the right in the perspective view of the figure, of its path which it can reach. The oscillatory body 28 plugged onto the pin 26 as well as onto the stationary pin 29 is disposed at the righthand reversal point of its path.

Markings 39, 40, which are aligned with one another, at a flange 41 of the gearwheel 32 protruding beyond the tooth rim and at the end wall 17 indicate a correct orientation of the gearwheel 32 and as a consequence thereof also of the tray 1 engaging by its axial spigot 14 in a cut-out, which is T-shaped in cross-section, of the gearwheel 32. A pair, which is redundant per se, of markings 42, 43 at the toothing 31 of the pivot body 28 and at the gearwheel 32 shows the correct positioning of gearwheel 32 and oscillatory body 31 with respect to one another.

A sensor 44 for detecting the rotational setting of the gearwheel 32 is mounted near this. It co-operates with a rib 45, which protrudes in axial direction from the edge of the flange 41 on a part of the circumference thereof so that it can enter into a slot at the rear side of the sensor housing. In the tilted setting of FIG. 3 the rib 45 is for the greatest part covered by the sensor 44 and the oscillatory body 28. FIG. 4 differs from FIG. 3 in that the housing of the sensor 44 is shown in part cut away so that two light barriers 46, 47 bridging over the slot can be recognised in its interior. The rib 45 is disposed closely above the two light barriers 46, 47 so that a control electronic system, which is not illustrated, can recognise, on the basis of the fact that the two light barriers are open, that the tray 1 is disposed in the tilted setting and can stop the drive motor 22 in order to be able to keep the tray 1 in the tilted setting and fill it.

After a predetermined water quantity has been admetered to the tray 1 under the control of the control circuit the drive motor 22 is set in operation by the control unit in order to bring the tray I into the upright setting in which the water quantities in the compartments 4 of the tray 1 are cleanly separated from one another. This setting is shown in FIG. 5 in a perspective view corresponding with FIG. 2 and in FIG. 6 in a front view corresponding with FIG. 4. The gearwheel 25 is further rotated in clockwise sense relative to the setting of FIG. 4, although the same setting of the tray 1 can also be reached by rotation of the gearwheel 25 in counter-clockwise sense. Attainment of the upright setting is recognised when the rib 45 begins to block the lower light barrier 47.

The tray 1 remains in the upright setting for such a length of time until the water in the compartments 4 is frozen. The dwell time in the upright setting can be fixedly predetermined; alternatively, the control circuit can also be connected with a temperature sensor in order to be able to establish, on the basis of a measured temperature in the environment of the tray 1 and a characteristic curve stored in the control circuit, a respective time period sufficient in the case of the measured temperature for freezing the water.

After expiry of this time period the drive motor 22 is set back into operation in order to rotate the gearwheel 25 into the setting shown in FIG. 8, with the pin 26 in the 9 o'clock position. The control circuit recognises that this position is reached when the two light barriers 46, 47 are again open. The rib 45 is now able to be clearly seen in the figure for a major part of its length.

In this setting the compartments 4 of the tray 1 are downwardly open so that the pieces of ice contained therein can drop out. The already mentioned electric heating device 13 is provided in order to facilitate release of the pieces of ice. As can be recognised in FIG. 9, this heating device 13 is an electric heating rod, which is bent into a loop and which extends in close contact with the tray 1 between heat exchange ribs 49 protruding at the underside thereof and is in part received in a groove 48 formed at the underside of the tray 1.

Through brief heating of the tray 1 with the help of the heating device 13 the pieces of ice in the compartments 4 are thawed at the surface. The water layer thus produced between the tray 1 and the pieces of ice acts as a slide film on which the pieces of ice are movable with very low friction. By virtue of the cross-sectional shape of the compartments 4 in the form of a segment of a cylinder the pieces of ice easily slide out of the compartments 4 and drop into a collecting container (not illustrated) arranged below the ice maker.

After emptying of the compartments 4, the drive motor is set back into operation and the gearwheel 25 further rotated in clockwise sense until it again reaches the setting shown in FIGS. 2 to 4 and a new operating cycle of the ice maker begins.

FIG. 10 schematically shows a modified embodiment of the ice maker in a front view. The ice maker has a frame corresponding with the frame 15 of FIG. 1, of which in the figure only two pins 29 are illustrated. The tray 1 and the gearwheel 32 mounted on the axial spigot 14 thereof are identical with those of FIG. 1. An oscillatory body 28 has two horizontal slots 20, in which the pins 29 engage so that the oscillatory body is horizontally guided to be displaceable.

A wheel 25 driven by a motor 22 directly or by way of a speed step-down transmission with constant sense of rotation carries a pin 26 which projects in axial direction and with which an end of a connecting rod 50 is pivotably connected. The other end is pivotably connected with the oscillatory body 28. The connecting rod 50 converts the circulatory motion of the eccentric pin into an oscillatory pivot motion of the tray 1 from the tilted setting via the illustrated upright setting to the emptying setting and back.

In a third embodiment shown in FIG. 11 the oscillatory body 28 is replaced by a gearwheel 51 which is rotatably suspended at the frame (not shown) and on the one hand meshes with the gearwheel 30 fastened to the axle section 14 of the tray and on the other hand is coupled by way of a connecting rod 50 with an eccentric pin 26 of the motor-driven wheel 25. The spacing of a joint 52 between connecting rod and axis of the gearwheel 51 is greater than the radius of the path of the pin, so that the gearwheel 51 is drivable by a rotation of the wheel 25 merely for an oscillatory pivot motion. This pivot motion is converted by a suitably selected translation ratio of the gearwheels 51 and 32 into the angular stroke required for movement of the tray between tilted setting and emptying setting. 

1-11. (canceled)
 12. An ice maker comprising: a frame; a tray which is pivotable in the frame about an axis and which has a plurality of compartments arranged in a number of rows and separated from one another by partition walls; and a motor for driving a pivot movement of the tray about the axis, wherein the tray is coupled to the motor by way of an eccentric mechanism.
 13. The ice maker according to claim 12, wherein the eccentric mechanism comprises a linearly displaceable oscillatory body which carries a rack meshing with a gearwheel connected with the tray.
 14. The ice maker according to claim 13, wherein the oscillatory body comprises a rail, which is oriented transversely to its direction of displacement and which is in engagement with an eccentric element driven by the motor on a circular path.
 15. The ice maker according to claim 14, wherein the rail is a slot and the eccentric element is a pin engaging in the slot.
 16. The ice maker according to claim 12, wherein the tray is pivotable between an upright setting in which the upper edges of the partition walls extend horizontally and an emptying setting in which the openings of the compartments face downwardly.
 17. The ice maker according to claim 12, wherein the tray is pivotable between an upright setting in which the upper edges of the partition walls extend horizontally and a tilted setting in which the compartments communicate via the upper edges of the partition walls.
 18. The ice maker according to claim 16, wherein the tray adopts one of the two settings when the oscillatory body is disposed at a point of reversal of its movement.
 19. The ice maker according to claim 18, further comprising a sensor for detecting at least the respective other one of the two settings of the tray.
 20. The ice maker according to claim 12, wherein the compartments each have the form of a segment of a body of rotation.
 21. The ice maker according to claim 12, further comprising a wall extending above the upper edge of the partition walls at a longitudinal side of each row of compartments and at least a part of the transverse sides thereof.
 22. The ice maker according to claim 12, further comprising an electric heating element mounted at the tray. 